He suggested to Einstein that space-time would be composed of five dimensions while Einstein was stating that space-time would be four dimensional.
Einstein said that normal space is three dimensional. That is typically expressed in mathematics as X, Y and Z.
Then one more dimension should be added. “Time”.
One day, one mathematician whose name was not so known well among academics at that time sent a short thesis to Einstein. There being described was general relativity based on not 4 dimensions but 5 dimensions that happened to reach Maxwellian equations for electromagnetism.
Einstein then encouraged him to publish the theory which later is developed into Kaluza–Klein theory. Klein is a Swedish theoretical physicist. They developed the theory.
Yes, at that time, Gravity was getting closer to Electro-Magnetism.
But, it was like small fire suddenly blight burned but then disappeared somehow. Instead, being left was excitement among academics seeking quantum mechanics. Until theory of string emerges, the idea of adding further dimension had been in hibernation.
Now a days, physics is quite a complicating thing but it also looks (to me) that physics has come to a deadlock. May be here the present being required is an idea, innovative and not deeply be “contaminated” one.
Like The Laws of Thought by George Boole, which now is the fundamental of computerized system, some ideas quietly and modestly alive may finally be of salvation to modern physics.
Today, my story is quite fell short of in terms of both length and consideration thus if someone who is professional in the field of physics read this, please just leave me as I am. I am just an innocent science-fiction-loving ordinally middle aged man.
Finally, I have to leave here a short statement for Ukrainian people.
Although nobody could stop it, we have to at least continue thinking of the way that can eliminate any form of war. At least we can say that some persons who are taking the situation seriously have started thinking of how to create peaceful world.